I sometimes fling out little jewels that may be regional idioms (not idiots) not out in the rest of the world. Most are not originals, but many are taken and used in different situations. The act of saying something I think is funny and no one understands is “Millerizing” someone . . . as in Dennis Miller and his unusual humor style that can leave his audience staring blankly.
I fell in love with “spitballing” watching the movie A Few Good Men when the Colonel was being VERY pointed and sarcastic with his friend the Major about sending an inferior Marine away to avoid the problems. In that movie it was a snotty way of making his friend feel inferior and put down.
I use it FAAARRR more playfully when poking a little fun at someone. It the same vain, but not mean-spirited.
[i]To make a suggestion loosely, often one that goes against common logic: "Now I'm just spitballing here, but why don't we pay off our loan in Canadian dollars and save ourselves some money?"[/i] (really old example . . now we'd being making money with Loonies)
Spitballing is a euphemism for Brainstorming or brain dumping. It comes from the metaphor of shooting pit balls against the wall to see which one(s) stick.